Object Oriented ABAP

Binding in ABAP Object Oriented Programming
Some basic terminologies
1.1 ABAP Objects
ABAP objects is the term given to object oriented programming done in ABAP. This
programming model unites data and functions. OO ABAP is built on existing ABAP language.
ABAP objects are run in same environment as the normal ABAP programs. OO ABAP is part
of ABAP since R/3 release 4.0
1.2 Class
Class is a prototype that defines data and the behaviour common to all the objects of
certain kind. Here methods provide the behaviour. We can say classes describe objects.
Classes can be declared either globally or locally. Global classes can be declared using
transaction SE24. Local classes are declared in an ABAP program (reports etc).
1.3 Objects
It signifies the real world. Technically we can say objects are instances of a class. We can
create any number of objects from a class template. All the objects created have unique
identity and each contain different set of attributes. Objects we create in a program exist
only till the program exists.
1.4 Encapsulation
Through encapsulation we restrict the visibility of attributes and methods in the object.
There are three levels of visibility in OO ABAP.
Public
Protected
Private
1.5 Polymorphism
The name of method is same but they behave differently in different classes. It means
implementation of method (i.e. body of the method) is different in different classes. It can
be achieved in two different ways in OO ABAP.
Interfaces
Overriding methods or redefining methods in each class after inheritance